We investigate the oxidation of aluminum low-index surfaces [(100), (110), and (111)] at low temperatures $(300–600\mathrm{K})$ and three different gas pressure values. We use molecular dynamics (MD) simulations with dynamic charge transfer between atoms where the interaction between atoms is described by the $\mathrm{Es}+$ potential composed of the embedded atom method (EAM) potential and an electrostatic contribution. In the considered temperature range and under different gas pressure conditions, the growth kinetics follow a direct logarithmic law where the oxide thickness is limited to a value of $\sim 3\mathrm{nm}$. The fitted curves allow us to determine the temperature and the pressure dependencies of the parameters involved in the growth law. During the adsorption stage, we observe a rotation of the oxygen pair as a precursor process to its dissociation. In most cases, the rotation aligns the molecule vertically to the Al surface. The separation distance after dissociation ranges from $3\text{to}9\mathrm{\AA }$. Atomistic observations revealed that the oxide presents a dominant tetrahedral $\left(\mathrm{Al}{\mathrm{O}}_4\right)$ environment in the inner layer and mixed tetrahedral and octahedral $\left(\mathrm{Al}{\mathrm{O}}_6\right)$ environments in the outer oxide region when the oxide thickness reaches values beyond $\sim 2\mathrm{nm}$.

The reactivity of the Ti–Al system was investigated experimentally in the case of reactive laminated particles produced by high energy ball milling. The ignition temperature for a self-sustaining reaction was measured as a function of the heating rate. By means of the Kissinger analysis, two activation energies were evaluated. The first one is associated with the solid-state transformation at the interface below the melting point of Al. The second one corresponds to the exothermic dissolution of Ti into Al liquid together with the formation of ${\mathrm{TiAl}}_3$ . A complementary microscopic approach was developed in order to detect all elemental processes associated with the reactivity of the Ti–Al system in composite materials. Above the melting temperature of Al, the exothermic dissolution of Ti into the liquid layer starts and induces a self-sustaining behavior until the reaction is complete. The dissolution step is limited by the low solubility of Ti in Al. The formation of the intermetallic compound ${\mathrm{TiAl}}_3$ was observed. The microscopic analysis of the dissolution at the interface explains some specific features of reactive particles.

This work focuses on a class of nano-laminated Ni/Al composites fabricated by a rolling-stacking procedure. This method results in nano-laminated composites with a complex structure. Their reactivity was compared with that of reactive multilayer nanofoils with constant bilayer thickness. Typical samples are composed of randomly distributed grains of Ni and Al. The self-propagating reactive front presents peculiarities that are directly related to the initial microstructure. The combustion mode is unsteady, with shifts in velocity. The temperature profile is characterized by broad combustion and post-combustion zones. The instantaneous shape of the front is tortuous, with the appearance of hot spots correlated with the underlying grain configuration. Local dynamics was studied in order to detect all the elemental processes occurring at nanoscale that trigger propagation: melting of Al, coarsening of Al grains, progressive exothermic dissolution mixing, heterogeneous nucleation, and growth of the intermetallic phase, $B$ 2-NiAl. The role of the complex initial microstructure was clearly demonstrated.